Find an explanation of why no revertants from mutant a

Assignment Help Biology
Reference no: EM1339932

A strain of Aspergillus was subjected to mutagenesis by X rays, and two tryptophan-requiring mutants ( A and B) were isolated. These tryptophan-requiring strains were plated in large numbers to obtain revertants to wild type. You failed to recover any revertants from mutants A and recovered one revertant from mutant B. This revertant was crossed with a normal wild-type strain. What proportion of the progeny from this cross would be wild type if

a) the reversion precisely reversed the original change that produced the typ- mutant allele?

b) the revertant phenotype was produced by a mutation in a second gene located on a different chromosome (the new mutation suppresses trp-)?

Propose an explanation of why no revertants from mutant A were recovered.

Reference no: EM1339932

Questions Cloud

Explain how has the sarbanes-oxley act : Explain How has the Sarbanes-Oxley Act (SOX) changed the system of corporate governance
Calculate wacc after tax : Capital Co. has a capital structure, based on current market values, that consists of 34 percent debt, 12 percent preferred stock, and 54 percent common stock.  Calculate WACC after tax in percent.
Computing value of the depreciation tax shield : The company has a marginal tax rate of 34 percent. What is the value of the depreciation tax shield?
It may be borne in mind which demand plays a pivotal role : It may be borne in mind which demand plays a pivotal role so far the determination of equilibrium composition of output is concerned.
Find an explanation of why no revertants from mutant a : the reversion precisely reversed the original change that produced the typ- mutant allele.
Logic of mercantilist ideas : What was mercantilism? Why did the logic of mercantilist ideas encourage King James to grant a charter to the Virginia Company?
Computing discounted payback period : The project has a 9 percent required rate of return and an initial cost of $2,800. What is the discounted payback period?
Explain why does a production possibilities curve bow : Explain why does a production possibilities curve bow out rather than forming a straight line sloping downward from left to right.
Concept of marginal utility : Newspaper vending machines are designed so that once you have paid for one paper,  Using the concept of marginal utility, explain why these vending machines differ.

Reviews

Write a Review

Biology Questions & Answers

  What fraction of total dna the target sequence constitute

The genome of virus SV40 is a circular double-stranded DNA molecule 5 kb long. A 1 kb region is amplified by PCR for four cycles. What fraction of total DNA does the target sequence constitute.

  Find the disorder and explain

select a chromosomal disorder from the March of Dimes Foundation Website.

  The likely gamete combinations of the offspring

Describe why you can predict that meiosis gives rise to genetic differences between parent's cells and daughter cells in fewer cell divisions than mitosis does.

  What is her diagnosis

A women is perspiring profusely with rapid breathing, breath smells like acetone and blood sugar is 650mg/ml, blood chemistry indicates acidosis, what is her diagnosis, is it hypoglicemia, but thrown off by rapid breathing.

  Genetic problems

What phenotypic ratio would you get if you crossed a white mouse and a heterozygous brown mouse?

  What effect ebv would have on b cell function

What effect do you think EBV would have on B cell function. What phenotypes would you expect in the F2, and in what actual numbers (not ratios) will you expect to find out them.

  Find the frequencies of the versions of this trait

Why or why not explain with reason? Work the genetics problem predicting the frequencies of the versions of this trait among their prospective children.

  Assume that an enzyme requires an active site

What percent of all the enzyme molecules will have their Cys thiol in the active form at pH 8.6. Some mammals might run or fight when frightened. For both of these examples, illustrate the physiological mechanisms involved in the answer.

  Hormone binds to g protein what is the hypothalamus

Nucleus, Mitochondria, How do receptors interact with hormones? How do the hormones interact with each Other? How do the secondary messengers work Again? Hormone binds to G protein what is the Hypothalamus.

  Nadh and fadh2 are transported along electron carriers

In eukaryotic cells, the electrons donated by NADH and FADH2 are transported along electron carriers in the

  How many generations would it take to eliminate

The trend in the U.S. is having children later in life than previous generations. What effects may this trend have on the incidence of late-acting dominant lethal alleles in the population.

  Draw a map of the f+ strain

Determine which of these would synthesize the enzymes for Histidine synthesis

Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd